Emigration timing of juvenile pond-breeding amphibians in western Massachusetts

Understanding the timing of movement events of pond-breeding amphibians to and from breeding and natal ponds, respectively, is essential to implementing effective conservation and monitoring strategies for this group of vertebrates. In this study, we assessed the emigration timing of newly metamorphosed juveniles of four species of pond-breeding amphibians (Ambystoma maculatum, Ambystoma opacum, Notophthalmus viridescens, and Rana sylvatica) in western Massachusetts from data collected at 14 seasonal ponds during four consecutive years (2000–2003). Results identified emigration “windows” for juveniles of each species during each year and for all years pooled. Additionally, analyses identified considerable intraspecific variation in the timing of emigration among ponds and years for at least three of the four study species. Our results are directly applicable to management strategies (e.g., road-closures) aimed at minimizing human-related impacts (e.g., road mortality) on populations of pond-breeding amphibians, as well as to mitigation strategies (e.g., maintaining engineered wetlands with an appropriate hydroperiod length) employed in cases of direct habitat loss